Wash the pollock fillet, dab dry, cut into large cubes and sprinkle with lemon juice. Cover and let it steep for a short time. Rinse the corn briefly and let it drip off. Wash and halve the tomato, remove the stalk and cut the tomato halves into slices.
Peel, halve and slice the onion. Dice cheese. Steam onion in 5 g fat in a pot for 5 minutes. Salt fish pieces, turn in flour and fry the rest of the fat in a small pan for about 10 minutes, turning several times.
Add the peas and corn to the onions and stew for 5 minutes. Fold in tomato wedges and season with salt and pepper. Mix vegetables and fish pieces and season to taste. Arrange on a preheated plate, sprinkle with cheese cubes and garnish with tarragon leaves as desired.